Importance: Studies comparing the efficacy of intra-arterial therapy (IAT) and medical therapy in reducing final infarct volume (FIV) in intracranial large-vessel occlusions (ILVOs) are lacking.
Objectives: To assess whether patients with ILVOs who received IAT have smaller FIVs than patients who received either intravenous tissue plasminogen activator therapy (IVT) or no reperfusion therapy (NRT) and to determine a National Institutes of Health Stroke Scale (NIHSS) threshold score that identifies patients most likely to benefit from IAT.
Design: Retrospective cohort study of patients with ILVOs between 2009 and 2011.
Setting: Two large-volume stroke centers.
Participants: Adults with anterior circulation ILVOs who presented within 360 minutes from the time last seen as normal. Patients with isolated extracranial occlusions were not included.
Exposure: Intra-arterial therapy, IVT, or NRT.
Main outcomes and measures: Final infarct volumes, rates of acceptable outcome defined as a modified Rankin Scale score of 0 to 3 at hospital discharge, and NIHSS threshold scores.
Results: A total of 203 consecutive patients with ILVOs were evaluated. Baseline characteristics were similar among the 3 groups. The median infarct volume was significantly smaller for the IAT group (42 cm3) than for the IVT group (109 cm3; P = .001) or the NRT group (110 cm3; P < .01). A higher magnitude of infarct volume reduction in more proximal occlusions was noted in the IAT group compared with the IVT and NRT groups combined: internal carotid artery terminus (75 vs 190 cm3; P < .001), M1 middle cerebral artery (39 vs 109 cm3; P = .004), and M2 middle cerebral artery (33 vs 59 cm3; P = .04) occlusions. Patients were stratified based on NIHSS score at presentation (8-13, 14-19, and ≥20). For patients with an NIHSS score of 14 or higher at presentation, IAT significantly reduced FIV (46 cm3 with IAT vs 149 cm3 with IVT or NRT; P < .001) compared with patients with an NIHSS score of 8 to 13 (22 cm3 with IAT vs 44 cm3 with IVT or NRT; P = .40). Patients with an NIHSS score of 14 or higher who received IAT appear to benefit most from IAT.
Conclusions and relevance: Our data suggest a greater reduction of FIV with IAT compared with either IVT or NRT. Moreover, patients with an NIHSS score of 14 or higher may be the best candidates for endovascular reperfusion therapy.